The invention relates to a method of providing telecommunication services in a telecommunication system comprising at least one terminal, a serving network providing the terminal with services, and at least one bearer network in functional connection with the serving network, the connection between the serving network and the terminal being established by means of a subscriber application comprised by the terminal.
The invention also relates to a telecommunication system comprising at least one terminal, a serving network providing the terminal with services, and at least one bearer network in functional connection with the serving network, the connection between the serving network and the terminal being established by means of a subscriber application comprised by the terminal.
The invention further relates to a network element in a telecommunication system, which network element is arranged to provide a telecommunication connection for a terminal by means of a subscriber application comprised by the terminal.
In various telecommunication systems, various subscriber or service data are often used for several purposes. Typically, a terminal utilizing telecommunication resources has to transmit its identifier to the telecommunication network, so that it can be distinguished from other terminals. Further, on the basis of the identifier, services of a certain quality level (QoS, Quality of Service) may be provided for the terminal in question. Also, various applications are required to identify a subscriber in a telecommunication system. Various smart-card based subscriber identification applications are widely used in telecommunication systems, especially in mobile systems, on the basis of which applications the subscriber can be identified and provided with services according to the subscriber agreement.
Third generation mobile communication systems have been developed in different parts of the world. The 3GPP (3rd Generation Partnership Ship Project) is in the process of standardizing the third generation mobile system UMTS (Universal Mobile Telecommunications System) based on the GSM system and comprising a new radio interface. The UMTS radio interface will be based on at least the WCDMA (Wideband Code Division Multiple Access) technology. The UMTS system will utilize the GSM core network, whereby connection management and mobility management will probably be to a great extent similar. The UMTS system will provide circuit-switched and packet-switched services. Packet-switched services will probably be based on the GPRS service (General Packet Radio Service) of the GSM.
All services of the UTMS system will not be standardized. The standardization will only concern certain basic services, whereby different mobile communication services and applications implementing these services can be developed, in which these basic services are utilized. It is therefore to be expected that, compared with the second generation mobile communication systems, the provision of services will increase considerably and new service providers will come onto the market.
To prevent misuse and to ensure reliable billing, in particular, subscriber identification is typically arranged in telecommunication systems, such as in the UMTS system. Before being able to use the services provided by the UMTS system, the subscriber has to make an agreement with the UMTS service provider. While a distinction can often be made between the user and the subscriber in telecommunication systems, in the present application it is assumed, for the sake of simplicity, that the subscriber is also the user.
In the UMTS specifications, the UMTS service provider corresponds to the home environment HE known as the home environment HE, which makes an agreement with the subscriber about the provision of services and gives the subscriber an identification application USIM (UMTS Subscriber Identity Module). Hereby, the home location register HLR comprising subscriber data is typically located in the home environment HE. The serving network SN refers to the network in the area of which the mobile station is at a given moment. In roaming and when the provision of services and the network operation are separate, the home environment HE and the serving network SN may be different. It is thus feasible that the home environment HE buys bearer services from the serving network SN.
The USIM application is usually stored on a smart card UICC (UMTS IC Card). The home environment HE owns the USIM application and typically also the smart card UICC. The services can only be used in the mobile network when the mobile station has the USIM available, an emergency call being the only exception. The USIM comprises the data required for the identification of the subscriber, such as a subscriber identifier IMSI (International Mobile Subscriber Identity). In some specifications, the identifier corresponding to the IMSI is IMUI (International Mobile User Identity). Typically, a temporary identifier TMSI (Temporary Mobile Subscriber Identity) specific to the current location area is also stored in the USIM application, by means of which identifier the transmission of the IMSI over the radio path can be avoided.
The USIM comprises authentication functions to authenticate the subscriber-representing USIM application in the network. The calculation of the cipher key is also performed in the USIM application. The verification of the subscriber is arranged at least by means of a PIN identifier (Personal Identity Number), whereby the USIM application may only be utilized by the user who knows the number. The USIM comprises data relating to the services and information about the location area, for example, updated by the serving network. The USIM application also contains memory for the subscriber's personal data; telephone numbers and short messages, for instance, can be stored in the USIM application.
The subscriber may need to make agreements with more than one home environment HE. For example, the subscriber may want to use a mobile network providing the most inexpensive services at a given time. As the USIM always belongs to one home environment HE, the subscriber now receives several USIM applications that may be on different smart cards. Typically, changing the USIM application to be used will also change the mobile network providing the radio connection.
It is also possible to use services of several different home environments through one serving network SN. The precondition for this is that the home environments have agreed to purchase network services from the serving network. FIG. 1 illustrates a telecommunication system in which a mobile station MS may be in connection with several home environments HEI, HE2, HE3 through one serving network VN. As subscriber identification applications are required for the use of each home environment HE, the subscriber needs three identification applications USIM1, USIM2 and USIM3.
In the UMTS system, one UICC card may contain several separate applications, such as USIM applications. If the mobile station supports substantially simultaneous use of several USIM applications, it may be possible to use several mobile communication services from different home environments. In phase 1 of the UMTS system, however, support is not required for the use of more than one USIM application.
A problem with the arrangement described above is the use or updating of subscriber identification applications, such as USIM applications, comprised by a terminal, especially a mobile station. The memory of a smart card is typically very limited and it is not possible to store large amounts of data on it. Modifying the memory of a smart card is difficult for the owner of the application, especially when operating over a radio connection, whereby the possibility of errors increases compared with a situation where a fixed line is used. Further, the connection between the smart card and the terminal may be slow for transmitting large amounts of data.
Using more than one identification application in a terminal may be difficult for the user, especially when the applications are on different smart cards. The terminal must also comprise means for supporting several subscriber identification applications substantially simultaneously and possibly on different smart cards, which adds to the complexity of the terminal.
When a smart card contains identification applications of several operators, it becomes problematic to guarantee security between different applications, and ownership and responsibility questions may also arise.
If identification applications belonging to several different owners, such as mobile station operators, are simultaneously used in a terminal, control signalling, such as location updating, is typically required for all applications separately. Hereby, the increase in signalling over the radio path in mobile systems causes a further problem.